It seems to be an undefined variable.

似乎是个未定义的变数。

youdao

Instead of checking for a default compound value, you can also catch the access to an undefined variable. E.g.

不用再检查默认的复合值，您也可以捕获对未定义变量的访问。

youdao

Your code includes some undefined variable that you have used as if it was already defined and initialized.

你的代码包括一些未定义的变量，你作为已经定义并初始化的来使用。

youdao